Yeah we went live Monday so I hope it’s right. 
The biggest difficulty was the lack of documentation for common scenarios like sheet metal. I gather most customers pay for epicor consultants to do it for them. Our use case was the sheet metal example pretty much as above and long-form material like structural steel and pipe. For the latter we just want to use in inches and order in common lengths like 16ft, 20ft. Easy. The idea on plate is to engineer and issue in any LxW dimension, order in pcs of common full sheet dimensions, and cost by LB. That all seems to be working.
One limitation is Epicor doesn’t presently track Supplier Price by AttributeSet so it’s not perfect. For example, 72”W SS costs more per LB than 48”W. It can’t do that. At Insights they said it was coming but they’re still working on it. We’ve seen a couple new areas light up around the Attribute feature set so I do believe it’ll happen. We ended up loading plate variants by width in addition to those without width in the description for this reason. We’ll see how it goes.
Happy to share more details lord knows info is wanting.